Cardboard containers with pour spouts that require the consumer to push in a section of one side wall and tear back the top wall of the carton have heretofore been constructed of a single line of perforations defining the pour spout. In many instances, the single line of perforations in the prior art containers may not sufficiently weaken the inner lining of the cardboard side wall thereby making it relatively difficult for the consumer to break the lining. Consequently, the consumer may be forced to resort to a knife or other utensil to open the container, thus defeating the purpose of the perforations. Additionally, even if the consumer is able to break the inner lining of the container by pushing on the single line of perforations, often the break will be an imperfect tearing of the side wall linings which may result in an inferior pour spout. The particles inside the container may become caught between the linings and it can be difficult to control the pouring of the particles.
An improvement in the prior art paperboard containers with pour spouts is shown in U.S. Pat. No. 3,981,430 issued to Keim. More particularly, U.S. Pat. No. 3,981,430 discloses a tab defined by a single line of perforations in a side wall of the container adjacent to the top wall. The walls of the container are further provided with arcuate fold lines that enable an enlarged pouring spout to be formed. However, the linings of the paperboard container must be broken and the consumer may still have to resort to extraneous materials to open the container if the single perforated line has not sufficiently weakened the side wall.
Other types of pour spout arrangements are disclosed in U.S. Pat. Nos. 3,618,847 issued to Koolnis; 3,570,745 issued to Aoki; and 3,262,630 issued to Koolnis. These all disclose an extra tab in the outside of the side wall to facilitate opening the carton and a single line of perforations along the edges of the top wall. The principal deficiency with this type of poor spout is that the tab may not be strong enough to break the single perforated lines on the top walls. Furthermore, the extra material required to provide the tab adds to the expense of manufacturing the carton.
U.S. Pat. No. 4,142,635 issued to Capo et al. discloses a pour spout formed by an extra tab of material in the inside layer of the top wall defined by a single line of perforations. The extra tab is adhesively secured to the outer layer of the container which also includes a tab defined by a single line of perforations. Thus, to open the carton shown in U.S. Pat. No. 4,142,635 the consumer must separate two distinct sets of single perforated lines which would probably require the use of a utensil.
U.S. Pat. No. 3,133,689 which issued to Rossi relates to a carton which includes an inner tab of material defined by a single line of perforations in the side wall. An outer tab is merely a layer of material adhesively secured to the inner tab lying outside the side wall. If the adhesive bond is not secure enough it may not be sufficient to separate the inner tab from the single line of perforations. Thus, the consumer would be forced to open the carton with an implement, such as a knife.
Accordingly, it is an object of the subject invention to provide an easy opening carton with an integral pour spout that can be opened without the use of extraneous utensils.
It is another object of the subject invention to provide an easy opening carton with an integral pour spout which permits the inner lining of the carton to be broken cleanly to facilitate pouring of the contents from the carton.
It is a further object of the subject invention to provide an easy opening carton with an integral pour spout that can be inexpensively manufactured from a single blank of paperboard material.
It is an additional object of the subject invention to provide an easy opening carton with an integral pour spout defined by a plurality of parallel lines of perforations.
It is yet another object of the subject invention to provide a single blank of paperboard material that can be formed into an easy opening carton with an integral pour spout.